Electric pump

ABSTRACT

An electric pump includes a motor, a pump, an electric pump case, a pressure sensor device to measure a pressure of fluid, and a circuit board. The pump includes a pump gear to rotate along with rotation of a shaft, and a pump body including a pump chamber recessed from a surface and housing the pump gear, and a through-hole with openings at two ends in an axial direction, one of the openings being opened to the pump chamber. The pressure sensor device includes a pressure sensor device body between the pump and the motor, and an electrical connection cable electrically connecting the pressure sensor device body and the circuit board. The electrical connection cable is routed from the pressure sensor device body to the circuit board inside of the electric pump case.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to an electric pump.

2. Description of the Related Art

An electric pump using a motor has been known. For example, a relatedart electric pump includes a pump unit and a motor unit, which areintegrated.

When the pressure of fluid such as oil pressurized by an electric pumpas described above is measured by a pressure sensor, the pressure sensorcan be disposed in the electric pump. However, this configurationrequires a wire for supplying power to the electric pump, and a wire forsupplying power to the pressure sensor. This complicates the work ofassembling the electric pump in some cases. In addition, the electricpump needs to be connected with the outside at two places, which leadsto an increase in the size of the electric pump in some cases.

SUMMARY OF THE INVENTION

Example embodiments of the present disclosure provide electric pumpseach including a pressure sensor device and having a structure thatreduces complication of assembly work and prevents an increase in size.

An electric pump according to an aspect of the present disclosureincludes: a shaft to rotate about a central axis extending in an axialdirection; a motor to rotate the shaft; a pump positioned on a firstside of the motor in the axial direction to be driven through the shaftby the motor; a tubular electric pump case that houses the shaft, themotor, and the pump and to which the motor and the pump are fixed; apressure sensor device to measure a pressure of fluid pressurized by thepump; and a circuit board positioned on a second side of the motor inthe axial direction and electrically connected with the motor. The pumpincludes a pump gear to rotate along with rotation of the shaft, and apump body including: a pump chamber recessed from a surface on the firstside in the axial direction toward the second side in the axialdirection and housing the pump gear; and a through-hole includingopenings at two ends in the axial direction through which the shaftpenetrates, the opening on the first side in the axial direction beingopened to the pump chamber. The pressure sensor device includes apressure sensor device body disposed between the pump and the motor inthe axial direction, and an electrical connection cable electricallyconnecting the pressure sensor device body and the circuit board. Theelectrical connection cable is routed from the pressure sensor devicebody to the circuit board through inside of the electric pump case in aradial direction.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating an electric pump accordingto an exemplary embodiment of the present disclosure.

FIG. 2 is a partially sectional perspective view illustrating anelectric pump according to an exemplary embodiment of the presentdisclosure.

FIG. 3 is a diagram illustrating a portion of the electric pumpaccording to an exemplary embodiment of the present disclosure, and is across-sectional view taken along in FIG. 1.

FIG. 4 is a plan view illustrating a portion of the electric pumpaccording to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An electric pump 10 according to an exemplary embodiment of the presentdisclosure is an electric oil pump configured to pressurize and transferoil as fluid. As illustrated in FIGS. 1 and 2, the electric pump 10includes an electric pump case 11, a shaft 21 configured to rotate abouta central axis J extending in an axial direction, a motor unit 20configured to rotate the shaft 21, a pump unit 30 configured to bedriven through the shaft 21 by the motor unit 20, a sensor magnet 140, abus bar unit 100, a circuit board 110, a rotation sensor 130, and apressure sensor device 50.

In the following description, unless otherwise stated, a directionparallel to the axial direction of the central axis J is simply referredto as an “axial direction”, a radial direction with respect to thecentral axis J is simply referred to as a “radial direction”, and acircumferential direction with respect to the central axis J is simplyreferred to as a “circumferential direction”. In addition, unlessotherwise stated, the upper side in the axial direction in FIG. 1 issimply referred to as an “upper side”, and the lower side in the axialdirection in FIG. 1 is simply referred to as a “lower side”. In theexemplary embodiment of the present disclosure, the lower sidecorresponds to one side in the axial direction, and the upper sidecorresponds to the other side in the axial direction. The upper side andthe lower side are names merely used for description, and do not limitactual positional relations and directions.

The electric pump case 11 is a tubular member that houses the motor unit20 and the pump unit 30 and to which the motor unit 20 and the pump unit30 are fixed. In FIG. 1, the electric pump case 11 includes a housing 12and a motor cover 13. The housing 12 has a cylindrical shape having acenter at the central axis J and openings at both ends in the axialdirection. The housing 12 holds the motor unit 20 and the pump unit 30inside. The motor cover 13 is attached to above the housing 12. Themotor cover 13 has a tubular shape opened on the lower side, andincludes, at an upper end, a lid covering the upper opening of thehousing 12.

The motor unit 20 includes a rotor 23 and a stator 22. The rotor 23 isfixed to the outer peripheral surface of the shaft 21. The stator 22 isdisposed along the circumferential direction on the outer side of theshaft 21 in the radial direction. More specifically, the stator 22 isdisposed on the outer side of the rotor 23 in the radial direction andsurrounds the rotor 23. The stator 22 includes a core back part 26 a, aplurality of teeth parts 26 b, an insulator 24, and a plurality of coils25.

As illustrated in FIG. 3, the core back part 26 a has an annular shape.More specifically, as illustrated in FIGS. 2 and 3, the core back part26 a has a cylindrical shape having a center at the central axis J. Theouter peripheral surface of the core back part 26 a is fixed to theinner peripheral surface of the housing 12. As illustrated in FIG. 3,the plurality of teeth parts 26 b extends from the core back part 26 ainward in the radial direction, and are disposed along thecircumferential direction. In FIG. 3, for example, 12 teeth parts 26 bare disposed at equal intervals along the circumferential direction.

The insulator 24 is mounted on the teeth parts 26 b. The plurality ofcoils 25 are wound around the plurality of teeth parts 26 b,respectively. More specifically, the plurality of coils 25 are woundaround the teeth parts 26 b through the insulator 24. FIG. 3 omitsillustration of the shaft 21 and the rotor 23.

As illustrated in FIG. 1, the pump unit 30 is positioned below the motorunit 20. The pump unit 30 includes a pump body 31, a pump gear 32, and apump cover 36. The pump body 31 is disposed below the motor unit 20,facing to the motor unit 20 in the axial direction with a gap interposedtherebetween. The pump body 31 includes a pump chamber 35 recessedupward from a lower surface and housing the pump gear 32. Although notillustrated, the pump chamber 35 has a circular shape when viewed in theaxial direction. The pump body 31 includes a through-hole 31 a havingopenings at both ends in the axial direction through which the shaft 21penetrates, the lower opening being opened to the pump chamber 35.

The pump body 31 includes a sensor housing recess 37 recessed downwardfrom an upper surface and housing a pressure sensor device body 54 to bedescribed later. The sensor housing recess 37 is disposed on the outerside of the through-hole 31 a in the radial direction. As illustrated inFIGS. 2 and 3, the sensor housing recess 37 has a circular ring shapehaving a center through which the central axis J passes. The pump body31 includes a seal holding part 38 protruding upward. The seal holdingpart 38 has a cylindrical shape having a center at the central axis Jand opened upward. The seal holding part 38 is disposed on the innerside of the sensor housing recess 37 in the radial direction. Asillustrated in FIG. 1, an oil seal 40 is held inside the seal holdingpart 38. The inside of the seal holding part 38 is communicated with thethrough-hole 31 a. The shaft 21 penetrates through the inside of theseal holding part 38.

The pump gear 32 rotates along with rotation of the shaft 21. In theexemplary embodiment of the present disclosure, the pump gear 32 isattached to a lower end part of the shaft 21. The pump gear 32 includesan inner rotor 33 fixed to an outer peripheral surface at the lower endpart of the shaft 21, and an outer rotor 34 surrounding the outside ofthe inner rotor 33 in the radial direction. The pump cover 36 isattached below the pump body 31. The pump cover 36 has a lid shapespreading in the radial direction. The pump cover 36 blocks the openingbelow the pump chamber 35. The inner rotor 33 and the shaft 21 may beallowed to relatively rotate about the central axis J to some extent.

The pump unit 30 includes an introduction oil path 91 and a dischargingoil path 92. In FIG. 1, the introduction oil path 91 is provided to thepump cover 36. The introduction oil path 91 is an oil path that isconnected with the pump chamber 35 and through which oil is taken intothe pump chamber 35. In FIG. 1, the discharging oil path 92 is providedto the pump body 31. The discharging oil path 92 is an oil path that isconnected with the pump chamber 35 and through which oil is dischargedfrom the pump chamber 35. The pump body 31 includes a detection oil path93. The detection oil path 93 is an oil path connecting the dischargingoil path 92 and the sensor housing recess 37. In FIG. 1, the detectionoil path 93 extends obliquely upward from the discharging oil path 92toward the outer side in the radial direction.

The sensor magnet 140 has a circular ring shape having a center throughwhich the central axis J passes. The sensor magnet 140 is attached tothe shaft 21 through an attachment member 141 engaged and fixed to anupper end of the shaft 21. The sensor magnet 140 rotates together withrotation of the shaft 21.

The bus bar unit 100 is disposed above the motor unit 20. The bus barunit 100 includes a plurality of first bus bars 105 electricallyconnected with the stator 22, a plurality of second bus bars 106electrically connected with the circuit board 110, and a tubular bus barholder 101 holding the bus bars. The bus bar holder 101 includes abottom part 102 spreading in the radial direction, a cylindrical part103 extending upward from an outer edge of the bottom part 102 in theradial direction, and a tubular connector part 104 protruding from thecylindrical part 103 outward in the radial direction. A bearingsupporting an upper end part of the shaft 21 is held at the center ofthe bottom part 102. The connector part 104 is connected with anexternal device (not illustrated). The external device connected withthe connector part 104 is a device including, for example, a controlunit and a power source and configured to control the motor unit 20.

The first bus bars 105 and the second bus bars 106 are partiallyembedded and held in the bus bar holder 101. As illustrated in FIG. 4,one end of each first bus bar 105 protrudes from the inner peripheralsurface of the cylindrical part 103 inward in the radial direction. Theone ends of the first bus bars 105 are electrically connected with thecoils 25 through a wiring member (not illustrated). As illustrated inFIG. 1, the other end of each first bus bar 105 protrudes into theconnector part 104.

As illustrated in FIG. 4, the second bus bars 106 extend along adirection in which the connector part 104 extends. One end of eachsecond bus bar 106 is connected with an upper surface 110 a of thecircuit board 110. The other end of the second bus bar 106 protrudesinto the connector part 104. FIG. 4 omits illustration of the motorcover 13.

As illustrated in FIG. 1, the circuit board 110 has a plate shapespreading in the radial direction. The circuit board 110 is positionedabove the motor unit 20. The circuit board 110 is held by the bus barholder 101 on the inner side of the bus bar holder 101 in the radialdirection. In other words, the electric pump 10 includes the bus barholder 101 as a holder holding the circuit board 110. The circuit board110 is held by the bus bar holder 101 while being supported from belowby a protrusion protruding upward from the bottom part 102.

The rotation sensor 130 is electrically connected with the circuit board110. The rotation sensor 130 is attached to the lower surface of thecircuit board 110. The rotation sensor 130 faces to the sensor magnet140 in the axial direction with a gap interposed therebetween. In theexemplary embodiment of the present disclosure, the rotation sensor 130measures rotation of the motor unit 20 by detecting change in magneticflux from the sensor magnet 140. The rotation sensor 130 is, forexample, a Hall sensor, and three of the rotation sensors 130 areprovided along the circumferential direction.

As illustrated in FIG. 4, the electric pump 10 includes, as some of thesecond bus bars 106, a power terminal 111 for supplying power to therotation sensor 130, and a ground terminal 112 for grounding therotation sensor 130. The power terminal 111 and the ground terminal 112are electrically connected with the circuit board 110. The powerterminal 111 and the ground terminal 112 are electrically connected withthe external device connected with the connector part 104. In additionto the power terminal 111 and the ground terminal 112, the electric pump10 includes, as one of the second bus bars 106, an output terminal fortransferring a signal detected by the rotation sensor 130 to theexternal device. The power terminal 111, the ground terminal 112, andthe output terminal are electrically connected with the rotation sensor130 through printed wires (not illustrated) provided to the circuitboard 110.

When the connector part 104 is connected with the external device, thefirst bus bars 105 and the second bus bars 106 protruding into theconnector part 104 are electrically connected with the external device.The external device supplies power to the coils 25 through the first busbars 105. The external device supplies power to the rotation sensor 130through the power terminal 111 among the second bus bars 106. A signaldetected by the rotation sensor 130 is transferred to the externaldevice through the output terminal among the second bus bars 106. Thecontrol unit of the external device controls current supplied to thecoils 25 through the first bus bars 105 in accordance with the signalfrom the rotation sensor 130. Accordingly, drive of the motor unit 20 iscontrolled, and drive of the pump unit 30 is controlled. In this manner,in the exemplary embodiment of the present disclosure, when the externaldevice is connected with the connector part 104, the circuit board 110is electrically connected with the motor unit 20 through the externaldevice.

For example, the control unit of the external device may be attached tothe circuit board 110. In this case, the first bus bars 105 may beconnected with the circuit board 110 to supply power to the coils 25through the circuit board 110. With this configuration, the circuitboard 110 is electrically connected with the motor unit 20 also when theexternal device is not connected with the connector part 104.

The pressure sensor device 50 illustrated in FIGS. 1 to 3 measures thepressure of fluid pressurized by the pump unit 30, in other words, oilin the exemplary embodiment of the present disclosure. The pressuresensor device 50 is disposed in the electric pump 10. The pressuresensor device 50 includes the pressure sensor device body 54 and anelectrical connection cable 60. The pressure sensor device body 54 has aflat shape having a relatively small dimension in the axial direction.As illustrated in FIG. 3, in plan view, the pressure sensor device body54 has schematically a V shape having an apex pointing outward in theradial direction and having an obtuse opening angle. As illustrated inFIG. 1, the pressure sensor device body 54 is disposed between the pumpunit 30 and the motor unit 20 in the axial direction. More specifically,the pressure sensor device body 54 is fixed in the sensor housing recess37 by a screw.

The electrical connection cable 60 extends upward from the pressuresensor device body 54 and is connected with the circuit board 110. Theelectrical connection cable 60 electrically connects the pressure sensordevice body 54 and the circuit board 110. The electrical connectioncable 60 is routed from the pressure sensor device body 54 to thecircuit board 110 through the inside of the electric pump case 11 in theradial direction.

In this manner, the electrical connection cable 60 extends from thepressure sensor device body 54 disposed in the electric pump 10 throughthe inside of the electric pump 10 and is connected with the circuitboard 110. With this configuration, electrical connection between thepressure sensor device 50 and the outside is shared with electricalconnection between the motor unit 20 and the outside through the circuitboard 110. This simplifies wiring at the pressure sensor device 50 andthe motor unit 20 in the electric pump 10, and reduces complication ofassembly work of the electric pump 10. In addition, connection with theoutside only occurs at the connector part 104 connected with theexternal device for controlling the motor unit 20, which leads toreduction of increase in the size of the electric pump 10. Accordingly,according to the exemplary embodiment of the present disclosure, it ispossible to obtain the electric pump 10 having a structure with whichcomplication of the assembly work is reduced and the size increase isreduced.

According to the exemplary embodiment of the present disclosure, sincethe pressure sensor device body 54 is housed in the sensor housingrecess 37, increase in the size of the electric pump 10 in the axialdirection can be reduced. In addition, since oil in the discharging oilpath 92 flows into the sensor housing recess 37 through the detectionoil path 93 connected with the sensor housing recess 37, the pressure ofoil pressurized by the pump unit 30 can be measured by the pressuresensor device body 54.

As illustrated in FIG. 3, the electrical connection cable 60 is routedfrom the pressure sensor device body 54 to the circuit board 110 througha gap between the teeth parts 26 b adjacent to each other in thecircumferential direction. In this manner, the electrical connectioncable 60 can be routed through the gap in the stator 22, whicheliminates the need to redundantly form a path through which theelectrical connection cable 60 is routed, and allows simplification ofthe configuration of the electric pump 10.

More specifically, the electrical connection cable 60 is routed througha gap between the coils 25 adjacent to each other in the circumferentialdirection. The electrical connection cable 60 includes a first lead line61, a second lead line 62, and a third lead line 63. The first lead line61, the second lead line 62, and the third lead line 63 are bundled in acover tube. Each lead line is any one of a power lead line for supplyingpower to the pressure sensor device body 54, a ground lead line forgrounding the pressure sensor device body 54, and an output lead linefor outputting, as an electric signal, a pressure value measured by thepressure sensor device body 54. In the exemplary embodiment of thepresent disclosure, as an example, the first lead line 61 is a powerlead line, the second lead line 62 is a ground lead line, and the thirdlead line 63 is an output lead line.

As illustrated in FIG. 4, the first lead line 61 is connected with theupper surface 110 a of the circuit board 110 through a first connectionterminal 161. The second lead line 62 is connected with the uppersurface 110 a of the circuit board 110 through a second connectionterminal 162. The third lead line 63 is connected with the upper surface110 a of the circuit board 110 through a third connection terminal 163.

The first connection terminal 161 is connected with the power terminal111 through a printed wire 170 provided on the upper surface 110 a ofthe circuit board 110. Accordingly, the first lead line 61 as a powerlead line is electrically connected with the power terminal 111. Thesecond connection terminal 162 is connected with the ground terminal 112through a printed wire 170 provided on the upper surface 110 a of thecircuit board 110. Accordingly, the second lead line 62 as a ground leadline is electrically connected with the ground terminal 112. Thus, thepower terminal 111 and the ground terminal 112 of the rotation sensor130 are used in common as a power terminal and a ground terminal of thepressure sensor device 50. This eliminates the need to provide a powerterminal and a ground terminal for the pressure sensor device 50, whichleads to reduction of the number of terminals connected with the circuitboard 110.

As illustrated in FIG. 2, the electric pump 10 includes a first fixationpart 120 fixing the electrical connection cable 60 to the bus bar holder101, and a second fixation part 39 fixing the electrical connectioncable 60 to the pump body 31. Thus, it is easy to route the electricalconnection cable 60 straight along the axial direction without slack,thereby reducing movement of the electrical connection cable 60 in theelectric pump 10. Accordingly, when the electrical connection cable 60is disposed between the teeth parts 26 b as in the exemplary embodimentof the present disclosure, the electrical connection cable 60 can beprevented from contacting the rotor 23.

In the exemplary embodiment of the present disclosure, the firstfixation part 120 is a clasp fixed to the bus bar holder 101. The firstfixation part 120 includes a first grasping part 121 and a firstattachment part 122. As illustrated in FIG. 4, the first grasping part121 has a substantially U shape in plan view and grasps an upper endpart of the electrical connection cable 60. As illustrated in FIG. 1,the first attachment part 122 is fixed to the bottom part 102. The firstattachment part 122 is inserted, from above the bottom part 102, into ahole penetrating through the bottom part 102 in the axial direction. Thefirst attachment part 122 has a lower end part exposed below the bottompart 102 and twisted about the axis of a hole through which the firstattachment part 122 penetrates. With this configuration, the firstattachment part 122 is fixed to the bottom part 102.

As illustrated in FIG. 2, in the exemplary embodiment of the presentdisclosure, the second fixation part 39 is a clasp fixed to the pumpbody 31. The second fixation part 39 includes a second grasping part 39a and a second attachment part 39 b. As illustrated in FIG. 3, thesecond grasping part 39 a has a substantially U shape in plan view andgrasps a lower end part of the electrical connection cable 60. Asillustrated in FIG. 2, the second attachment part 39 b is fixed to thepump body 31 by a screw 70. More specifically, the second attachmentpart 39 b is fixed to the bottom surface of the sensor housing recess 37by the screw 70 fastened to the bottom surface of the sensor housingrecess 37.

The pressure sensor device body 54 is supplied with power from theexternal device connected with the connector part 104 through the powerterminal 111, the printed wire 170, the first connection terminal 161,and the first lead line 61. An electric signal of a pressure valuemeasured by the pressure sensor device body 54 is output to the externaldevice connected with the connector part 104 through the third lead line63, the third connection terminal 163, the printed wire (notillustrated), and the output terminal of the rotation sensor 130. Thecontrol unit of the external device adjusts the amount of currentsupplied to the motor unit 20 in accordance with the input pressurevalue, thereby controlling the amount of oil transferred by the pumpunit 30. Accordingly, the pressure of oil pressurized by the pump unit30 is adjusted.

The electrical connection cable 60 only needs to be routed through theinside of the electric pump case 11 in the radial direction, but therouting is not particularly limited. For example, a through-holepenetrating though the core back part 26 a in the axial direction, or agroove recessed from the outer peripheral surface of the core back part26 a inward in the radial direction and opened at both ends of the coreback part 26 a in the axial direction may be provided so that theelectrical connection cable 60 is routed through the through-hole or thegroove. Alternatively, for example, part of a side wall part of thehousing may protrude outward in the radial direction so that theelectrical connection cable 60 is routed through a gap between theprotruding part of the side wall part of the housing 12 and the coreback part 26 a in the radial direction.

The pressure sensor device body 54 only needs to be disposed between thepump unit 30 and the motor unit 20 in the axial direction, and may beprovided at a place other than the inside of the sensor housing recess37. For example, the pressure sensor device body 54 may be fixed to themotor unit 20. The configuration of the pressure sensor device body 54,such as the shape thereof, is not particularly limited.

In the above description, the first fixation part 120 is a memberseparated from the bus bar holder 101, but is not limited thereto. Thebus bar holder 101 and the first fixation part 120 may be provided asparts of a single member. In the above description, the second fixationpart 39 is a member separated from the pump body 31, but is not limitedthereto. The pump body 31 and the second fixation part 39 may beprovided as parts of a single member.

The present disclosure is also applicable to an electric pump configuredto pressurize and transfer fluid other than oil.

The above-described configurations may be combined with each other asappropriate as long as mutual inconsistency therebetween is avoided.

Features of the above-described preferred embodiments and themodifications thereof may be combined appropriately as long as noconflict arises.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

1-5. (canceled) 6: An electric pump comprising: a shaft to rotate abouta central axis extending in an axial direction; a motor to rotate theshaft; a pump positioned on a first side of the motor in the axialdirection to be driven through the shaft by the motor; a tubularelectric pump case that houses the shaft, the motor, and the pump and towhich the motor and the pump are fixed; a pressure sensor device tomeasure a pressure of fluid pressurized by the pump; and a circuit boardpositioned on a second side of the motor in the axial direction andelectrically connected with the motor; wherein the pump includes: a pumpgear to rotate along with rotation of the shaft; and a pump bodyincluding a pump chamber recessed from a surface on the first side inthe axial direction toward the second side in the axial direction andhousing the pump gear, and a through-hole including openings at two endsin the axial direction through which the shaft penetrates, the openingon the first side in the axial direction being opened to the pumpchamber; the pressure sensor device includes: a pressure sensor devicebody disposed between the pump and the motor in the axial direction; andan electrical connection cable electrically connecting the pressuresensor device body and the circuit board; and the electrical connectioncable is routed from the pressure sensor device body to the circuitboard through an inside of the electric pump case in a radial direction.7: The electric pump according to claim 6, wherein the pump includes: anintroduction oil path through which the fluid is taken into the pumpchamber; and a discharging oil path through which the fluid isdischarged from the pump chamber; and the pump body includes: a sensorhousing recess recessed from a surface on the second side in the axialdirection toward the first side in the axial direction and housing thepressure sensor device body; and a detection oil path connecting thedischarging oil path and the sensor housing recess. 8: The electric pumpaccording to claim 6, wherein the motor includes a stator disposed alonga circumferential direction on an outer side of the shaft in the radialdirection; the stator includes: an annular core back; a plurality ofteeth extending from the core back inward in the radial direction anddisposed along the circumferential direction; and a plurality of coilswound around the plurality of teeth, respectively; and the electricalconnection cable is routed from the pressure sensor device body to thecircuit board through a space between the teeth adjacent to each otherin the circumferential direction. 9: The electric pump according toclaim 6, further comprising: a rotation sensor electrically connectedwith the circuit board to measure rotation of the motor; a powerterminal electrically connected with the circuit board to supply powerto the rotation sensor; and a ground terminal electrically connectedwith the circuit board to ground the rotation sensor; wherein theelectrical connection cable includes: a power lead line to supply powerto the pressure sensor device body; and a ground lead line to ground thepressure sensor device body; the power lead line is electricallyconnected with the power terminal; and the ground lead line iselectrically connected with the ground terminal. 10: The electric pumpaccording to claim 6, further comprising: a holder holding the circuitboard; a first connector to fix the electrical connection cable to theholder; and a second connector to fix the electrical connection cable tothe pump body.